1. Field of the Invention
The present invention relates generally to the field of shotgun ammunition, and more particularly, to a shotgun cartridge capable of exploding with a loud noise and producing low mass, low energy fragments which do not pose a serious risk of injury to persons close to the explosion and which provides a bright visible light during flight of the cartridge to thereby provide visual signaling.
2. Description of the Related Art
In recent years, United States armed forces and law enforcement agencies have put a greater emphasis on creating “less-lethal” weaponry. The purpose of such weapons is not to kill, but to temporarily incapacitate or, in some cases, to deter the subject from further approach. As an example, the U.S. Marine Corps. has required a shotgun round capable of delivering a “flash-bang” air burst at ranges of 400 feet, 600 feet, and 800 feet. This less-lethal “flash-bang” cartridge was intended for crowd control and to determine intent at extended stand-off ranges.
“Flash-bang” shotgun cartridges, used mostly for frightening animals (particularly birds) away from a specific location, are well-known in the prior art. Flash-bang cartridges are fired like any other shotgun rounds (See, FIG. 1, taken from FIG. 1 of U.S. Pat. No. 3,323,456). However, these prior art flash-bang cartridges have several shortcomings which make them less than ideal as a less-lethal weapon or deterrent force.
U.S. Pat. No. 3,323,456 to Rothman (the '456 patent) discloses a flash-bang shotgun cartridge comprised of a propellant charge and a projectile. Referring to FIG. 2 (FIG. 3 of the '456 patent), the projectile assembly 27 contains flash-bang charge 43 sealed between seal 39 in the front of the assembly and ballistic weight 35 in the rear of the assembly (see, col. 4, line 65 to col. 5, line 30, '456 patent). Ballistic weight 35 “impart[s] a higher flight coefficient and thus [extends] the range of the projectile” (see, col. 5, lines 29-30, '456 patent), is comprised of powdered lead and zinc (see, col. 5, lines 2-6, '456 patent), and its center 33 holds a fuse cord 37, which is lit by the propellant charge 25 (see, col. 5, lines 64-65, '456 patent).
The '456 patent has a ballistic weight which extends the range of the projectile (to distances as great as 900 feet; see, col. 4, lines 6-12 and col. 6, lines 1-3); however, the '456 patent's weighty mass is located in the rear of the projectile, which causes tumbling in flight and, thus, inaccurate targeting.
U.S. Pat. No. 3,062,144 to Hori et al. (the '144 patent) discloses a flash-bang shotgun cartridge that has delay fuse powder in a hollow center cylinder in the back of the projectile. As shown in FIG. 3 (FIG. 4 of the '144 patent), the fuse powder charge 35 is enclosed within cylindrical casing 34, where the cylindrical casing 34 extends outwardly (from the projectile) to the propellant charge 25 and inwardly to the flash-bang charge 42 (see, col. 2, lines 42-49, '144 patent).
However, the '144 patent does not disclose a weighty mass positioned in the projectile for greater distance, accuracy, and stability. The front of the projectile according to the '144 patent has a chamber 48 which can hold powdered material 42 (see, FIG. 3). The only payload material suggested by the '144 patent for the forward chamber is an additional powder charge (see, col. 2, lines 61-65, '144 patent). Because of the lack of ballistic weight, the projectile described by the '144 patent can not achieve long or accurate trajectories, but will instead tumble in flight and fall quickly to the ground.
Therefore, there is a need for a flash-bang shotgun cartridge which has greater stability in flight, as well as greater accuracy in targeting. Furthermore, there is a need for a flash-bang cartridge which will have a minor concussive effect upon a target, without causing serious harm.